Generation of magnetic field during inflation can explain its presence over a wide range of scales in the Universe. In [Sharma et al Phys. Rev. D 96, 083511 (2017)], we proposed a model to generate these fields during inflation. These fields have nonzero anisotropic stress which lead to the generation of a stochastic background of gravitational waves (GW) in the early universe. Here we show that for a scenario of magnetogenesis where reheating takes place around QCD epoch, this stochastic GW background lies in the 95% confidence region of the stochastic common spectrum process probed by NANOGrav collaboration. This is the case when the generated electromagnetic field (EM) energy density is 3%-10% of the background energy density at the end of reheating. For this case, the values of magnetic field strength B-0 similar to (0.7-1.4) x 10(-11) G and its coherence length similar to 3 kpc at the present epoch. These values are for the models in which EM fields are of nonhelical nature. For the helical nature of the fields, these values are B-0 similar to (2.1-3.8) x 10(-10) G and its coherence length similar to 90 kpc.
QC 20220325